Expression of functional luteinising hormone receptor and its messenger ribonucleic acid in bovine cervix: luteinising hormone augmentation of intracellular cyclic AMP, phosphate inositol and cyclooxygenase

The effect of luteinising hormone (LH) on bovine cervical tissues from thre e phases of the estrous cycle was studied. It was found that in the luteal phase cervix contained an LH receptor mRNA transcript and the 93 kDa LH rec eptor protein. Incubation of cervical minces from luteal phase with LI-I si gnificantly increased (P < 0.05) the intracellular concentrations of LH rec eptor protein, cAMP, inositol phosphate (IP) and cyclooxygenase as well as the production of prostaglandin (PG) E-2 (but not PGF(2 alpha)). In contras t in the pre-oestrus/oestrus or post-ovulatory cervix, the signal for the t ranscript for LH receptor and the LH receptor protein was significantly low er than luteal cervix (P < 0.05) and the tissue did not respond to LH. We c onclude that bovine cervix at luteal phase has high levels of LH receptor m RNA and receptor protein associated with the protein coupled receptor famil y that mediates cAMP and IP signalling responses. The receptors are coupled to PG synthase and generate cervical PGE(2) (C) 1999 Elsevier Science Irel and Ltd. All rights reserved.